Orientation detection for digital cameras

ABSTRACT

This patent describes a print roll for use in an instant camera device, the print roll having a ink return tray for collecting excess waste ink from the printing process. The return tray can comprises a sponge-like strip affixed to a leaf portion of the print roll.

CROSS REFERENCES TO RELATED APPLICATIONS

The following U.S. patent applications, identified by their U.S. patent application serial numbers (USSN), were filed simultaneously to the present application on Jul. 10, 1998, and are hereby incorporated by cross-reference: U.S. Ser. Nos. 09/113,060; 09/113,070; 09/113,073; 09/112,748; 09/112,747; 09/112,776; 09/112,750; 09/112,746; 09/112,743; 09/112,742; 09/112,741; 09/112,740; 09/112,739; 09/113,053; 09/112,738; 09/113,067; 09/113,063; 09/113,069; 09/112,744; 09/113,058; 09/112,777; 09/113,224; 09/112,804; 09/112,805; 09/113,072; 09/112,785; 09/112,797; 09/112,796; 09/113,071; 09/112,824; 09/113,090; 09/112,823; 09/113,222; 09/112,786; 09/113,051; 09/112,782; 09/113,056; 09/113,059; 09/113,091; 09/112,753; 09/113,055; 09/113,057; 09/113,054; 09/112,752; 09/112,759; 09/112,757; 09/112,758; 09/113,107; 09/112,829; 09/112,792; 09/112,791; 09/112,790; 09/112,789; 09/112,788; 09/112,795; 09/112,749; 09/112,784; 09/112,783; 09/112,763; 09/112,762; 09/112,737; 09/112,761; 09/113,223; 09/112,781; 09/113,052; 09/112,834; 09/113,103; 09/113,101; 09/112,751; 09/112,787; 09/112,802; 09/112,803; 09/113,097; 09/113,099; 09/113,084; 09/113,066; 09/112,778; 09/112,779; 09/113,077; 09/113,061; 09/112,818; 09/112,816; 09/112,772; 09/112,819; 09/112,815; 09/113,096; 09/113,068; 09/113,095; 09/112,808; 09/112,809; 09/112,780; 09/113,083; 09/113,121; 09/113,122; 09/112,793; 09/112,794; 09/113,128; 09/113,127; 09/112,756; 09/112,755; 09/112,754; 09/112,811; 09/112,812; 09/112,813; 09/112,814;,09/112,764; 09/112,765; 09/112,767; 09/112,768; 09/112,807; 09/112,806; 09/112,820; 09/112,821; 09/112,822; 09/112,825; 09/112,826; 09/112,827; 09/112,828; 09/113,111; 09/113,108; 09/113,109; 09/113,123; 09/113,114; 09/113,115; 09/113,129; 09/113,124; 09/113,125; 09/113,126; 09/113,119; 09/113,120; 09/113,221; 09/113,116; 09/113,118; 09/113,117; 09/113,113; 09/113,130; 09/113,110; 09/113,112; 09/113,087; 09/113,074; 09/113,089; 09/113,088; 09/112,771; 09/112,769; 09/112,770; 09/112,817; 09/113,076; 09/112,798; 09/112,801; 09/112,800; 09/112,799; 09/113,098; 09/112,833; 09/112,832; 09/112,831;:09/112,830; 09/112,836; 09/112,835; 09/113,102; 09/113,106; 09/113,105; 09/113,104; 09/112,810; 09/1129766; 09/113,085; 09/113,086; 09/113,094; 09/112,760; 09/112,773; 09/112,774; 09/112,775; 09/112,745; 09/113,092; 09/113,100; 091113,093; 09/113,062; 09/113,064; 09/113,082; 09/113,081; 09/113,080; 09/113,079; 09/113,065; 09/113,078; 09/113,075.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not applicable.

FIELD OF THE INVENTION

The present invention relates to an image processing method and apparatus and, in particular, discloses an Orientation Detection for Digital Cameras.

The present invention further relates to digital cameras and the processing of images produced from digital cameras.

BACKGROUND OF THE INVENTION

Recently, digital cameras have become increasingly popular. These cameras normally operate by means of imaging a desired image utilising a charge coupled device (CCD) array and storing the imaged scene on an electronic storage medium for later down loading onto a computer system for subsequent manipulation and printing out. Normally, when utilising a computer system to print out an image, sophisticated software may available to manipulate the image in accordance with requirements.

Unfortunately such systems require significant post processing of a captured image and normally present the image in an orientation to which is was taken, relying on the post processing process to perform any necessary rotations.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide an apparatus for the automatic detection of a camera's orientation and for the subsequent utilization of the orientation in the production of digital images directly by said camera.

In accordance with the present invention there is provided a camera system having:

an area image sensor means for sensing an image;

an image storage means for storing the sense image;

an orientation means for sensing the camera's orientation when sensing the image; and

a processing means for processing said sensed image utilising said sensed camera orientation.

BRIEF DESCRIPTION OF THE DRAWINGS

Notwithstanding any other forms which may fall within the scope of the present invention, preferred forms of the invention will now be described, by way of example only, with reference to the accompanying drawings which:

FIG. 1 illustrates a schematic example of image orientation specific processing; and

FIG. 2 illustrates a method of producing an image specific effect when utilising a camera as constructed in accordance with the preferred embodiment.

DESCRIPTION OF PREFERRED AND OTHER EMBODIMENTS

The preferred embodiment is preferable implemented through suitable programming of a hand held camera device such as that described in Australian Provisional Patent Application entitled “Image Processing Method and Apparatus (ART01)” filed concurrently herewith by the present applicant the content of which is hereby specifically incorporated by cross reference.

The aforementioned patent specification discloses a camera system, hereinafter known as an “Artcam” type camera, wherein sensed images can be directly printed out by an Artcam portable camera unit. Further, the aforementioned specification discloses means and methods for performing various manipulations on images captured by the camera sensing device leading to the production of various effects in any output image. The manipulations are disclosed to be highly flexible in nature and can be implemented through the insertion into the Artcam of cards having encoded thereon various instructions for the manipulation of images, the cards hereinafter being known as Artcards. The Artcam further has significant onboard processing power by an Artcam Central Processor unit (ACP) which is interconnected to a memory device for the storage of important data and images.

In the preferred embodiment the aforementioned Artcam includes an apparatus for the automatic detection of a cameras orientation which is subsequently utilized in the production of digital images. The Artcam is then suitably programmed utilizing the orientation information in image production.

A number of examples of utilization of orientation information will be now be described with reference to the accompanying drawings. Turning to FIG. 1, there is illustrated a first portrait photograph 1 wherein an area 2 is provided for the overlaying of information relevant to the portrait 1, such as date and location information entered via the camera system. Further, it is envisaged that the portrait 1 may be subjected to image processing techniques which distort certain visual portions of the image such as the face etc. These distortions rely upon detection of the orientation of the camera taking the photograph 1. There is also shown in FIG. 1, a second portrait mode image 3 wherein the camera has been utilised in a rotated portrait mode. Unfortunately if the image data 2 of the landscape mode image 1 is placed in the same position, it will appear in the area 5 in the final image which is an undesirable position. Ideally, the image specific information should appear in a place 6 when the image taken in a portrait mode. Further, image processing effects which are applied to the image in an orthogonal, anisotropic, image content specific manner will be ineffectual when the image is rotated.

Turning now to FIG. 2, there is illustrated the a method of utilisation of the Artcam device as described in the aforementioned Australian Provisional Patent Application with the numbers referring to those reference numeral as set out in the aforementioned specification.

The orientation sensor 46 senses an orientation which is converted by the ACP 31 into a corresponding digital orientation angle. The area image sensor 2 senses the image taken by the camera which is forwarded to the ACP 31 and stored within memory storage device 33. Next, the sensed orientation is utilised to determine whether a portrait or landscape mode image has been taken. The sensed image can be scanned in from memory store 33 and rotated before again being outputed to memory store 33. The final result being a rotated image 8. Alternatively, other techniques for utilisation of the sensed orientation information are possible. For example, the sensed image stored within memory 33 can have stored associated with it, the orientation information utilising the traditional rotational matrix system mapping a world coordinate system and local coordinate system mapping. Subsequently, computer graphic algorithms wishing to process the information can utilise the coordinate system during processing so as to operate on the image in a rotated orientation. Where position sensitive information eg. 6 of FIG. 1 is to be incorporated in the image, this text can be positioned in the correct orientation. Further, the orientation of the camera can be utilised in any image specific algorithmic techniques applied to the image such as face detection. The utilisation of the orientation information substantially simplifies any face detection algorithm as the face orientations will be approximately known.

The orientation sensor can comprise a simple and inexpensive gravity switch, such as a mercury switch, or can be a more complex miniature device such as a micro machined silicon accelerometer.

It would be appreciated by a person skilled in the art that numerous variations and/or modifications may be made to the present invention as shown in the specific embodiment without departing from the spirit or scope of the invention as broadly described. The present embodiment is, therefore, to be considered in all respects to be illustrative and not restrictive.

The presently disclosed ink jet printing technology is potentially suited to a wide range of printing systems including: colour and monochrome office printers, short run digital printers, high speed digital printers, offset press supplemental printers, low cost scanning printers, high speed pagewidth printers, notebook computers with inbuilt pagewidth printers, portable colour and monochrome printers, colour and monochrome copiers, colour and monochrome facsimile machines, combined printer, facsimile and copying machines, label printers, large format plotters, photograph copiers, printers for digital photographic ‘minilabs’, video printers, PhotoCD printers, portable printers for PDAs, wallpaper printers, indoor sign printers, billboard printers, fabric printers, camera printers and fault tolerant commercial printer arrays.

Ink Jet Technologies

The embodiments of the invention use an ink jet printer type device. Of course many different devices could be used. However presently popular ink jet printing technologies are unlikely to be suitable.

The most significant problem with thermal ink jet is power consumption. This is approximately 100 times that required for high speed, and stems from the energy-inefficient means of drop ejection. This involves the rapid boiling of water to produce a vapor bubble which expels the ink. Water has a very high heat capacity, and must be superheated in thermal ink jet applications. This leads to an efficiency of around 0.02%, from electricity input to drop momentum (and increased surface area) out.

The most significant problem with piezoelectric ink jet is size and cost. Piezoelectric crystals have a very small deflection at reasonable drive voltages, and therefore require a large area for each nozzle. Also, each piezoelectric actuator must be connected to its drive circuit on a separate substrate. This is not a significant problem at the current limit of around 300 nozzles per print head, but is a major impediment to the fabrication of pagewidth print heads with 19,200 nozzles.

Ideally, the ink jet technologies used meet the stringent requirements of in-camera digital color printing and other high quality, high speed, low cost printing applications. To meet the requirements of digital photography, new ink jet technologies have been created. The target features include:

low power (less than 10 Watts)

high resolution capability (1,600 dpi or more)

photographic quality output

low manufacturing cost

small size (pagewidth times minimum cross section)

high speed (<2 seconds per page).

All of these features can be met or exceeded by the ink jet systems described below with differing levels of difficulty. Forty-five different ink jet technologies have been developed by the Assignee to give a wide range of choices for high volume manufacture. These technologies form part of separate applications assigned to the present Assignee as set out in the list under the heading Cross References to Related Applications.

The ink jet designs shown here are suitable for a wide range of digital printing systems, from battery powered one-time use digital cameras, through to desktop and network printers, and through to commercial printing systems.

For ease of manufacture using standard process equipment, the print head is designed to be a monolithic 0.5 micron CMOS chip with MEMS post processing. For color photographic applications, the print head is 100 mm long, with a width which depends upon the ink jet type. The smallest print head designed is covered in U.S. patent application Ser. No. 09/112,764, which is 0.35 mm wide, giving a chip area of 35 square mm. The print heads each contain 19,200 nozzles plus data and control circuitry.

Ink is supplied to the back of the print head by injection molded plastic ink channels. The molding requires 50 micron features, which can be created using a lithographically micromachined insert in a standard injection molding tool. Ink flows through holes etched through the wafer to the nozzle chambers fabricated on the front surface of the wafer. The print head is connected to the camera circuitry by tape automated bonding.

Tables of Drop-on-Demand Ink Jets

The present invention is useful in the field of digital printing, in particular, ink jet printing. A number of patent applications in this field were filed simultaneously and incorporated by cross reference.

Eleven important characteristics of the fundamental operation of individual ink jet nozzles have been identified. These characteristics are largely orthogonal, and so can be elucidated as an eleven dimensional matrix. Most of the eleven axes of this matrix include entries developed by the present assignee.

The following tables form the axes of an eleven dimensional table of ink jet types.

Actuator mechanism (18 types)

Basic operation mode (7 types)

Auxiliary mechanism (8 types)

Actuator amplification or modification method (17 types)

Actuator motion (19 types)

Nozzle refill method (4 types)

Method of restricting back-flow through inlet (10 types)

Nozzle clearing method (9 types)

Nozzle plate construction (9 types)

Drop ejection direction (5 types)

Ink type (7 types)

The complete eleven dimensional table represented by these axes contains 36.9 billion possible configurations of ink jet nozzle. While not all of the possible combinations result in a viable ink jet technology, many million configurations are viable. It is clearly impractical to elucidate all of the possible configurations. Instead, certain ink jet types have been investigated in detail. Forty-five such inkjet types were filed simultaneously to the present application.

Other ink jet configurations can readily be derived from these forty-five examples by substituting alternative configurations along one or more of the 11 axes. Most of the forty-five examples can be made into ink jet print heads with characteristics superior to any currently available ink jet technology.

Where there are prior art examples known to the inventor, one or more of these examples are listed in the examples column of the tables below. The simultaneously filed patent applications by the present applicant are listed by USSN numbers. In some cases, a print technology may be listed more than once in a table, where it shares characteristics with more than one entry.

Suitable applications for the ink jet technologies include: Home printers, Office network printers, Short run digital printers, Commercial print systems, Fabric printers, Pocket printers, Internet WWW printers, Video printers, Medical imaging, Wide format printers, Notebook PC printers, Fax machines, Industrial printing systems, Photocopiers, Photographic minilabs etc.

The information associated with the aforementioned 11 dimensional matrix are set out in the following tables.

Description Advantages Disadvantages Examples ACTUATOR MECHANISM (APPLIED ONLY TO SELECTED INK DROPS) Thermal bubble An electrothermal heater heats Large force generated High power Canon Bubblejet 1979 the ink to above boiling point, Simple construction Ink carrier limited Endo et al GB patent transferring significant heat No moving parts to water 2,007,162 to the aqueous ink. A bubble Fast operation Low efficiency Xerox heater-in-pit nucleates and quickly forms, Small chip area High temperatures 1990 Hawkins et al expelling the ink. required for actuator required USP 4,899,181 The efficiency of the process High mechanical stress Hewlett-Packard TIJ is low, with typically less than Unusual materials required 1982 Vaught et al 0.05% of the electrical energy Large drive transistors USP 4,490,728 being transformed into kinetic Cavitation causes energy of the drop. actuator failure Kogation reduces bubble formation Large print heads are difficult to fabricate Piezo-electric A piezoelectric crystal Low power consumption Very large area required Kyser et al such as lead lanthanum Many ink types can be used for acuator USP 3,946,398 zirconate (PZT) is Fast operation Difficult to integrate with Zoltan electrically activated, High efficiency electronics USP 3,683,212 and either expands, shears, High voltage drive 1973 Stemme or bends to apply pressure transistors required USP 3,747,120 to the ink, ejecting drops. Full pagewidth print heads Epson Stylus impractical due to acuator size Tektronix Requires electrical poling USSN 09/112,803 in high field strengths during manufacture Electro- An electric field is used to Low power consumption Low maximum strain Seiko Epson, Usui et all strictive activate electrostriction in Many ink types can be used (approx. 0.01%) JP 253401/96 relaxor materials such as lead Low thermal expansion Large area required for USSN 09/112,803 lanthanum zirconate titanate Electric field strength actuator due to low strain (PLZT) or lead magnesium required Response speed is marginal niobate (PMN). (approx. 3.5 V/μm) (˜10 μs) can be generated without High voltage drive transistors difficulty Full pagewidth print heads Does not require electrical impractical due to actuator poling size Ferro- An electric field is used to Low power consumption Difficult to integrate USSN 09/112,803 electric induce a phase transition Many ink types can be used with electronics between the antiferroelectric Fast operation (<1 μs) Unusual materials such as (AFE) and ferroelectric (FE) Relatively high PLZSnT are required phase. Perovskite materials longitudinal strain Actuators require a large such as tin modified lead High efficiency area lanthanum zirconate titanate Electric field strength (PLZSnT) exhibit large strains of around 3 V/μm can be of up to 1% associated with readily provided the AFE to FE phase transition. Electro- Conductive plates are Low power consumption Difficult to operate USSN 09/112,787; static separated by a compressible Many ink types can be used electrostatic devices in an 09/112,803 plates or fluid dielectric (usually Fast operation aqueous environment air). Upon application of a The electrostatic actuator voltage, the plates attract will normally need to be each other and displace ink, separated from the ink causing drop ejection. Very large area required to The conductive plates may be achieve high forces in a comb or honeycomb High voltage drive transistors structure, or stacked to may be required increase the surface area and Full pagewidth print heads are therefore the force not competitive due to actuator size Electro- A strong electric field is Low current consumption High voltage required 1989 Saito et al, static pull applied to the ink, Low temperature May be damaged by sparks USP 4,799,068 on ink whereupon electrostatic due to air breakdown 1989 Miura et al, attraction accelerates the ink Required field strength USP 4,810,954 towards the print medium. increases as the drop size Tone-jet decreases High voltage drive transistors required Electrostatic field attracts dust Permanent An electromagnet directly Low power consumption Complex fabrication USSN 09/113,084; magnet attracts a permanent magnet, Many ink types can be used Permanent magnetic material 09/112,779 electro- displacing ink and causing Fast operation such as Neodymium Iron magnetic drop ejection. High efficiency Boron (NdFeB) required. Rare earth magnets with a Easy extension from single High local currents required field strength around 1 Tesla nozzles to pagewidth print Copper metalization should be can by used. heads used for long Examples are: Samarium electromigration lifetime Cobalt (SaCo) and magnetic and low resistivity materials in the neodymium Pigmented inks are usually iron boron family infeasible (NdFeB, NdDyFeBNb, Operation temperature limited NdDyFeB, etc) to the Curie temperature (around 540 K) Soft A solenoid induced a Low power consumption Complex fabrication USSN 09/112,751; magnetic magnetic field in a soft Many ink types can be used Materials not usually present 09/113,097; 09/113,066; core magnetic core or yoke Fast operation in a CMOS fab such as NiFe, 09/112,779; 09/113,061; electro- fabricated from a ferrous High efficiency CoNiFe, or CoFe are required 09/112,816; 09/112,772; magnetic material such as electroplated Easy extension from single High local currents 09/112,815 iron alloys such as CoNiFe nozzles to pagewidth print required [1], CoFe, or NiFe alloys. heads Copper metalization should be Typically, the soft used for long magnetic material is in two electromigration lifetime parts, which are normally and low resistivity held apart by a spring. Electroplating is required When the solenoid is High saturation flux density actuated, the two parts is required (2.0-2.1 T attract, displacing is achievable with the ink. CoNiFe [1]) Lorenz force The Lorenz force acting on a Low power consumption Force acts as a twisting USSN 09/113,099; current carrying wire in a Many ink types can be used motion 09/113,077; 09/112,818; magnetic field is utilized. Fast operation Typically, only a quarter 09/112,819 This allows the magnetic field High efficiency of the solenoid length to be supplied externally to Easy extension from single provides force in a useful the print head, for example nozzles to pagewidth print direction with rare earth permanent heads High local currents magnets. required Only the current carrying wire Copper metalization should be need be fabricated on the used for long print-head, simplifiying electromigration lifetime materials requirements. and low resistivity Pigmented inks are usually infeasible Magneto- The actuator uses the giant Many ink types can be used Force acts as a twisting Fischenbeck, striction magnetostrictive effect of Fast operation motion USP 4,032,929 materials such as Terfenol-D Easy extension from single Unusual materials such as USSN 09/113,121 (an aloy of terbium, nozzles to pagewidth print Terfenol-D are required dysprosium and iron heads High local currents required developed at the Naval High force is available Copper metalization should be Ordnance Laboratory, hence used for long Ter-Fe-NOL). For best electromigration lifetime efficiency, the actuator and low resistivity should be pre-stressed Pre-stressing may be to approx. 8 MPa. required Surface Ink under positive pressure Low power consumption Requires supplementary Silverbrook, tension is held in a nozzle by Simple construction force to effect drop EP 0771 658 A2 reduction surface tension. The surface No unusual materials separation and related patent tension of the ink is reduced required in fabrication Requires special ink applications below the bubble threshold, High efficiency surfactants causing the ink to egress Easy extension from single Speed may be limited by from the nozzle. nozzles to pagewidth surfactant properties print heads Viscosity The ink viscosity is locally Simple construction Requires supplementary force Silverbrook, reduction reduced to select which drops No unusual materials to effect drop separation EP 0771 658 A2 are to be ejected. A viscosity required in fabrication Requires special ink and related patent reduction can be achieved Easy extension from single viscosity properties applications electrothermally with most nozzles to pagewidth High speed is difficult to inks can be engineered for a print heads achieve 100:1 viscosity reduction. Requires oscillating ink pressure A high temperature difference (typically 80 degrees) is required Acousitc An acoustic wave is Can operate without Complex drive circuitry 1993 Hadimioglu et al, generated and focussed a nozzle plate Complex fabrication EUP 550,192 upon the drop Low efficiency 1993 Elrod et al, ejection region. Poor control of drop position EUP 572,220 Poor control of drop volume Thermo- An actuator which relies upon Low power consumption Efficient aqueous operation USSN 09/112,802; elastic bend differential thermal expansion Many ink types can be used requires a thermal insulator 09/112,778; 09/112,815; actuator upon Joule heating is used. Simple planar fabrication on the hot side 09/113,096; 09/113,068; Small chip area required Corrosion prevention can be 09/113,095; 09/112,808; for each actuator difficult 09/112,809; 09/112,780; Fast operatoin Pigmented inks may be 09/113,083; 09/112,793; High efficiency infeasible, as pigment 09/112,794; 09/113,128; CMOS compatible voltages particles may jam the bend 09/113,127; 09/112,756; and currents actuator 09/112,755; 09/112,754; Standard MEMS processes 09/112,811; 09/112,812; can be used 09/112,813; 09/112,814; Easy extension from single 09/112,764; 09/112,765; nozzles to pagewidth 09/112,767; 09/112,768 print heads High CTE A material with a very high High force can be Requires special material USSN 09/112,778; thermo- coefficient of thermal generated (e.g. PTFE) 09/112,815; 09/113,096; elastic expansion (CTE) such as Three methods of PTFE Requires a PTFE depostion 09/113,095; 09/112,808; actuator polytetrafluoroethylene deposition are under process, which is not yet 09/112,809; 09/112,780; (PTFE) is used. development: chemical standard in ULSI fabs 09/113,083; 09/112,793; As high CTE materials are vapor deposition (CVD), PTFE deposition cannot be 09/112,794; 09/113,128; usually non-conductive, a spin coating, and followed with high 09/113,127; 09/112,756; heater fabricated from a evaporation temperature (above 09/112,807; 09/112,806; conductive material is PTFE is a candidate for 350° C.) processing 09/112,820; incorporated. A 50 μm long low dielectric constant Pigmented inks may be PTFE bend actuator with insulation in ULSI infeasible, as pigment polysilicon heater and 15 mW Very low power particles may jam the power input can provide consumption bend actuator 180 μN force and 10 μm Many ink types can be used deflection. Simple planar fabrication Actuator motions include: Small chip area required Bend for each actuator Push Fast operation Buckle High efficiency Rotate CMOS compatible voltages and currents Easy extension from single nozzles to pagewidth print heads Conductive A polymer with a high High force can be Requires special materials USSN 09/113,083 polymer coefficient of thermal generated development (High CTE thermo- expansion (such as PFTE) Very low power conductive polymer) elastic is doped with conducting consumption Requires a PTFE depostion actuator substances to increase its Many ink types can be used process, which is not yet conductivity to about 3 Simple planar fabrication standard in ULSI fabs orders of magnitude below Small chip area required PTFE deposition cannot be that of copper. The for each actuator followed with high conducting polymer expands Fast operation temperature (above when resistively heated. High efficiency 350° C.) processing Examples of conducting CMOS compatible voltages Evaporation and CVD dopants include: and currents deposition techniques cannot Carbon nanotubes Easy extension from single be used Metal fibers nozzles to pagewidth Pigmented inks may be Conductive polymers such as print heads infeasible, as pigment doped polythiophene particles may jam the Carbon granules bend actuator Shape memory A shape memory alloy such as High force is available Fatigue limits maximum USSN 09/113,122 alloy TiNi (also known as (stresses of hundreds of number of cycles Nitinol - Nickel Titanium MPa) Low strain (1%) is required alloy developed at the Naval Large strain is available to extend fatigue resistance Ordnance Laboratory) is (more than 3%) Cycle rate limited by heat thermally switched between High corrosion resistance removal its weak martensitic state Simple construction Requires unusual materials and its high stiffness Easy extension from single (TiNi) austenic state. The shape of nozzles to pagewidth The latent heat of the actuator in its martensitic print heads tranformation must be state is deformed relative Low voltage operation provided to the austenic shape. The High current operation shape change causes ejection Requires pre-stressing to of a drop. distort the martensitic state Linear Linear magnetic actuators Linear Magnetic actuators Requires unusual USSN 09/113,061 Magnetic include the Linear Induction can be constructed with semiconductor materials Actuator Actuator (LIA), Linear high thrust, long travel, such as soft magnetic alloys Permanent Magnet and high efficiency using (e.g. CoNiFe) Synchronous Actuator planar semiconductor Some varieties also require (LPMSA), Linear Reluctance fabrication techniques permanent magnetic materials Synchronous Acuator Long sctuator travel is such as Neodymium iron Synchronous Actuator available boron (NdFeB) (LRSA), Linear Switched Medium force is available Requires complex multi-phase Reluctance Actuator (LSRA), Low voltage operation drive circuitry and the Linear Stepper High current operation Actuator (LSA). BASIC OPERATION MODE Acutator This is the simplest mode Simple operation Drop repetition rate is Thermal ink jet directly of operation: the actuator No external fields required usually limited to around Piezoelectric ink jet pushes ink directly supplies sufficient Satellite drops can be 10 kHz. USSN 09/112,751; kinetic energy to expel the avoided if drop velocity However, this is not 09/112,787; 09/112,802; drop. The drop must have a is less than 4 m/s fundamental to the method, 09/112,803; 09/113,097; sufficient velocity to Can be efficient, but is related to the refill 09/113,099; 09/113,084; overcome the surface depending upon the method normally used 09/112,778; 09/113,077; tension. actuator used All of the drop kinetic 09/113,061; 09/112,816; energy must be provided 09/112,819; 09/113,095; by the actuator 09/112,809; 09/112,780; Satellite drops usually form 09/113,083; 09/113,121; if drop velocity is greater 09/113,122; 09/112,793; than 4.5 m/s 09/112,794; 09/113,128; 09/113,127; 09/112,756; 09/112,755; 09/112,754; 09/112,811; 09/112,812; 09/112,813; 09/112,814; 09/112,764; 09/112,765; 09/112,767; 09/112,768; 09/112,807; 09/112,806; 09/112,820 Proximity The drops to be printed are Very simple print head Requires close proximity Silverbrook, EP selected by some manner fabrication can be used between the print head 0771 658 A2 and related (e.g. thermally induced The drop selection means and the print media or patent applications surface tension reduction does not need to provide transfer roller of pressurized ink). the energy required to May require two print heads Selected drops are separated separate the drop from printing alternate rows of from the ink in the nozzle the nozzle the image by contact with the print Monolithic color print heads medium or a transfer roller. are difficult Electro- The drops to be printed are Very simple print head Requires very high Silverbrook, EP static pull selected by some manner fabrication can be used electrostatic field 0771 658 A2 and related on ink (e.g. thermally induced The drop selection means Electrostatic field for small patent applications surface tension reduction of does not need to provide nozzle sizes is above air Tone-Jet pressurized ink). the energy required to breakdown Selected drops are separated separate the drop from Electrostatic field may from the ink in the nozzle by the nozzle attract dust a strong electric field. Magnetic The drops to be printed are Very simple print head Requires magnetic ink Silverbrook, EP pull on ink selected by some manner fabrication can be used Ink colors other than black 0771 658 A2 and related (e.g. thermally induced The drop selection means are difficult patent applications surface tension reduction of does not need to provide Requires very high pressurized ink). the energy required to magnetic fields Selected drops are separated separate the drop from from the ink in the nozzle by the nozzle a strong magnetic field acting on the magnetic ink. Shutter The actuator moves a shutter High speed (>50 kHz) Moving parts are required USSN 09/112,818; to block ink flow to the operation can be achieved Requires ink pressure 09/112,815; 09/112,808 nozzle. The ink pressure is due to reduced refill time modulator pulsed at a multiple of the Drop timing can be very Friction and wear must be drop ejection frequency. accurate considered The actuator energy can be Stiction is possible very low Shuttered grill The actuator moves a shutter Actuators with small travel Moving parts are required USSN 09/113,066; to block ink flow through a can be used Requires ink pressure 09/112,772; 09/113,096; grill to the nozzle. The Actuators with small force modulator 09/113,068 shutter movement need only can be used Friction and wear must be be equal to the width of the High speed (>50 kHz) considered grill holes. operation can be achieved Stiction is possible Pulsed The pulsed magnetic field Extremely low energy Requires an external pulsed USSN 09/112,779 magnetic attracts an ‘ink pusher’ operation is possible magnetic field pull on ink at the drop ejection frequency. No heat dissipation Requires special materials pusher An actuator controls a catch, problems for both the actuator and which prevents the ink pusher the ink pusher from moving when a drop is Complex construction not to be ejected. AUXILIARY MECHANISM (APPLIED TO ALL NOZZLES) None The actuator directly fires Simplicity of construction Drop ejection energy Most ink jets, including the ink drop, and there is no Simplicity of operation must be supplied by piezoelectric and thermal external field or other Small physical size individual nozzle actuator bubble. mechanism required. USSN 09/112,751; 09/112,787; 09/112,802; 09/112,803; 09/113,097; 09/113,084; 09/113,078; 09/113,077; 09/113,061; 09/112,816; 09/113,095; 09/112,809; 09/112,780; 09/113,083; 09/113,121; 09/113,122; 09/112,793; 09/112,794; 09/113,128; 09/113,127; 09/112,756; 09/112,755; 09/112,754; 09/112,811; 09/112,812; 09/112,813; 09/112,814; 09/112,764; 09/112,765; 09/112,767; 09/112,768; 09/112,807; 09/112,806; 09/112,820 Oscillating The ink pressure oscillates, Oscillating ink pressure Requires external ink Silverbrook, EP ink pressure providing much of the drop can provide a refill pulse, pressure oscillator 0771 658 A2 and related (including ejection energy. The actuator allowing higher operating Ink pressure phase and patent applications accoustic selects which drops are to be speed amplitude must be USSN 09/113,066; stimulation) fired by selectively blocking The actuators may operate carefully controlled 09/112,818; 09/112,772; or enabling nozzles. with much lower energy Acoustic reflections in the 09/112,815; 09/113,096; The ink pressure Acoustic lenses can be used ink chamber must be 09/113,068; 09/112,808 oscillation may be achieved to focus the sound on the designed for by vibrating the print head, nozzles or preferably by an actuator in the ink supply. Media The print head is placed in Low power Precision assembly required Silverbrook, EP proximity close proximity to the print High accuracy Paper fibers may cause 0771 658 A2 and related medium. Selected drops Simple print head problems patent applications protrude from the print construction Cannot print on rough head further than unselected substrates drops, and contact the print medium. The drop soaks into the medium fast enough to cause drop separation. Transfer roller Drops are printed to a transfer High accuracy Bulky Silverbrook, EP roller instead of straight to the Wide range of print Expensive 0771 658 A2 and related print medium. A transfer substrates can be used Complex construction patent applications roller can also be used for Ink can be dried on the Tektronix hot melt proximity drop separation. transfer roller piezoelectric ink jet Any of USSN 09/112,751; 09/112,787; 09/112,802; 09/112,803; 09/113,097; 09/113,099; 09/113,084; 09/113,066; 09/112,778; 09/112,779; 09/113,077; 09/113,061; 09/112,818; 09/112,816; 09/112,772; 09/112,819; 09/112,815; 09/113,096; 09/113,068; 09/113,095; 09/112,808; 09/112,809; 09/112,780; 09/113,083; 09/113,121; 09/113,122; 09/112,793; 09/112,794; 09/113,128; 09/113,127; 09/112,756; 09/112,755; 09/112,754; 09/112,811; 09/112,812; 09/112,813; 09/112,814; 09/112,764; 09/112,765; 09/112,767; 09/112,768; 09/112,807; 09/112,806; 09/112,820; 09/112,821 Electro- An electric field is used Low power Field strength required for Silverbrook, EP static to accelerate selected drops Simple print head separation of small drops 0771 658 A2 and related towards the print medium. construction is near or above air patent applications breakdown Tone-Jet Direct A magnetic field is used to Low power Requires magnetic ink Silverbrook, EP magnetic accelerate selected drops Simple print head Requires strong magnetic field 0771 658 A2 and related field of magnetic ink towards the construction patent applications print medium. Cross The print head is placed in a Does not require magnetic Requires external magnet USSN 09/113,099; magnetic constant magnetic field. The materials to be integrated Current densities may be high, 09/112,819 field Lorenz force in a current in the print head resulting in electromigration carrying wire is used to move manufacturing process problems the actuator. Pulsed A pulsed magnetic field is Very low power operation Complex print head USSN 09/112,779 magnetic used to cyclically attract a is possible construction field paddle, which pushes on the Small print head size Magnetic materials required ink. A small actuator moves a in print head catch, which selectively prevents the paddle from moving. ACTUATOR AMPLICFICATION OR MODIFICATION METHOD None No actuator mechanical Operational simplicity Many actuator mechanisms Thermal Bubble Ink jet amplification is used. The have insufficient travel, or USSN 09/112,751; actuator directly drives the insufficient force, to 09/112,787; 09/113,099; drop ejection process. efficiently drive the drop 09/113,084; 09/112,819; ejection process 09/113,121; 09/113,122 Differential An actuator material expands Provides greater travel High stresses are involved Piezoelectric expansion more on one side than on the in a reduced print Care must be taken that the USSN 09/112,802; bend actuator other. The expansion may be head area materials do no delaminate 09/112,778; 09/112,815; thermal, piezoelectric, Residual bend resulting 09/113,096; 09/113,068; magnetostrictive, or other from high temperature or 09/113,095; 09/112,808; mechanism. The bend actuator high stress during formation 09/112,809; 09/112,780; converts a high force low 09/113,083; 09/112,793; travel actuator mechanism 09/113,128; 09/113,127; to high travel, lower 09/112,756; 09/112,755; force mechanism. 09/112,754; 09/112,811; 09/112,812; 09/112,813; 09/112,814; 09/112,764; 09/112,765; 09/112,767; 09/112,768; 09/112,807; 09/112,806; 09/112,820 Transient A trilayer bend actuator Very good temperature High stresses are involved USSN 09/112,767; bend where the two outside layers stability Care must be taken that the 09/112,768 actuator are identical. This cancels High speed, as a new drop materials do not delaminate bend due to ambient can be fired before heat temperature and residual dissipates stress. The actuator only Cancels residual stress responds to transient heating of formation of one side or the other. Reverse spring The actuator loads a spring. Better coupling to the ink Fabrication complexity USSN 09/113,097; When the actuator is turned High stress in the spring 09/113,077 off, the spring releases. This can reverse the force/ distance curve of the actuator to make it compatible with the force/time requirements of the drop ejection. Actuator A series of thin actuators Increased travel Increased fabrication Some piezoelectric stack are stacked. This can be Reduced drive voltage complexity ink jets appropriate where actuators Increased possibility of USSN 09/112,803 require high electric field short circuits due to strength, such as electrostatic pinholes and piezoelectric actuators. Multiple Multiple smaller actuators are Increases the force Actuator forces may not add USSN 09/113,061; actuators used simultaneously to move available from an actuator linearly, reducing efficiency 09/112,818; 09/113,096; the ink. Each actuator need Multiple actuators can be 09/113,095; 09/112,809; provide only a portion of the positioned to control ink 09/112,794; 09/112,807; force required. flow accurately 09/112,806 Linear Spring A linear spring is used to Matches low travel actuator Requires print head area USSN 09/112,772 transform a motion with small with higher travel for the spring travel and high force into a requirements longer travel, lower force Non-contact method of motion. motion transformation Coiled actuator A bend actuator is coiled to Increases travel Generally restricted to planar USSN 09/112,815; provide greater travel in a Reduces chip area implementations due to 09/112,808; 09/112,811; reduced chip area. Planar implementations are extreme fabrication difficulty 09/112,812 relatively easy to fabricate. in other orientations. Flexure bend A bend actuator has a small Simple means of increasing Care must be taken not to actuator region near the fixture point, travel of a bend actuator exceed the elastic limit in which flexes much more the flexure area readily than the remainder of Stress distribution is very the actuator. The actuator uneven flexing is effectively Difficult to accurately USSN 09/112,779; converted from an even model with finite element 09/113,068; 09/112,754 coiling to an angular bend, analysis resulting in greater travel of the actuator tip. Catch The actuator controls a small Very low actuator energy Complex construction USSN 09/112,779 catch. The catch either Very small actuator size Requires external force enables or disables movement Unsuitable for pigmented inks of an ink pusher that is controlled in a bulk manner. Gears Gears can be used to increase Low force, low travel Moving parts are required USSN 09/112,818 travel at the expense of actuators can be used Several actuator cycles are duration. Circular gears, rack Can be fabricated using required and pinion, ratchets, and other standard surface More complex drive gearing methods can be used. MEMS processes electronics Complex construction Friction, friction, and wear are possible Buckle plate A buckle plate can be used to Very fast movement Must stay within elastic S. Hirata el al, “An change a slow actuator into a achievable limits of the materials for Ink-jet Head Using fast motion. It can also long device life Diaphragm convert a high force, low High stresses involved Microactuator”, Proc. travel actuator into a high Generally high power IEEE MEMS, February travel, medium force motion. requirement 1996, pp 418-423. USSN 09/113,096; 09/112,793 Tapered A tapered magnetice pole can Linearizes the magnetic Complex construction USSN 09/112,816 magnetic increase travel at the expense force/distance curve pole of force. Lever A lever and fulcrum is used to Matches low travel actuator High stress around the USSN 09/112,755; transform a motion with small with higher travel fulcrum 09/112,813; 09/112,814 travel and high force into a requirements motion with longer travel and Fulcrum area has no linear lower force. movement, and can be used The lever can also reverse the for a fluid seal direction of travel. Rotary The actuator is connected to a High mechanical advantage Complex construction USSN 09/112,794 impeller rotary impeller. A small The ratio of force to travel Unsuitable for pigmented angular deflection of the of the actuator can be inks actuator results in a rotation matched to the nozzle of the impeller vanes, which requirements by varying the push the ink against stationary number of impeller vanes vanes and out of the nozzle. Acoustic lens A refractive or diffractive No moving parts Large area required 1993 Hadimioglu et al, (e.g. zone plate) acoustic Only relevant for acoustic EUP 550,192 lens is used to concentrate ink jets 1993 Elrod et al, sound waves. EUP 572,220 Sharp A sharp point is used to Simple construction Difficult to fabricate using Tone-jet conductive concentrate an electrostatic standard VLSI processes for point field. a surface ejecting ink-jet Only relevant for electrostatic ink jets ACTUATOR MOTION Volume The volume of the actuator Simple construction in High energy is typically Hewlett-Packard expansion changes, pushing the ink in the case of thermal ink jet required to achieve volume Thermal Ink jet all directions. expansion. This leads to Canon Bubblejet thermal stress, cavitation, and kogation in thermal ink jet implementations Linear, The actuator moves in a Efficient coupling to ink High fabrication complexity USSN 09/112,751; normal to direction normal to the print drops ejected normal may be required to achieve 09/112,787; 09/112,803; chip surface head surface. The nozzle is to the surface perpendicular motion 09/113,084; 09/113,077; typically in the line of 09/112,816 movement. Parallel to The actuator moves parallel Suitable for planar Fabrication complexity USSN 09/113,061; chip surface to the print head surface. fabrication Friction 09/112,818; 09/112,772; Drop ejection may still be Stiction 09/112,754; 09/112,811; normal to the surface. 09/112,812; 09/112,813 Membrane An actuator with a high force The effective area of the Fabrication complexity 1982 Howkins push but small area is used to actuator becomes the Actuator size USP 4,459,601 push a stiff membrane that membrane area Difficulty of integration is in contact with the ink. in a VLSI process Rotary The actuator causes the Rotary levers may be used Device complexity USSN 09/113,097; rotation of some element, to increse travel May have friction at a 09/113,066; 09/112,818; such a grill or impeller Small chip area pivot point 09/112,794 requirements Bend The actuator bends when A very small change in Requires the actuator to be 1970 Kyser et al energized. This may be due dimensions can be made from at least two USP 3,946,398 to differential thermal converted to a large distinct layers, or to have a 1973 Stemme expansion, piezoelectric motion. thermal difference across USP 3,747,120 expansion, magnetostriction, the actuator 09/112,802; 09/112,778; or other form of relative 09/112,779; 09/113,068; dimensional change. 09/112,780; 09/113,083; 09/113,121; 09/113,128; 09/113,127; 09/112,756; 09/112,754; 09/112,811; 09/112,812 Swivel The actuator swivels around Allows operation where the Inefficient coupling to the USSN 09/113,099 a central pivot. This motion net linear force on the ink motion is suitable where there are paddle is zero opposite forces applied to Small chip area opposite sides of the paddle, requirements e.g. Lorenz force. Straighten The actuator is normally bent, Can be used with shape Requires careful balance of USSN 09/113,122; and straightens when memory alloys where the stresses to ensure that the 09/112,755 energized. austenic phase is planar quiescent bend is accurate Double bend The actuator bends in one One actuator can be used Difficult to make the drops USSN 09/112,813; direction when one element is to power two nozzles. ejected by both bend 09/112,814; 09/112,764 energized, and bends the other Reduced chip size. directions identical. way when another element is Not sensitive to ambient A small efficiency loss energized. temperature compared to equivalent single bend actuators. Shear Energizing the actuator Can increase the effective Not readily applicable 1985 Fishbeck causes a shear motion in the travel of piezoelectric to other actuator USP 4,584,590 actuator material. actuators mechanisms Radial The actuator squeezes an ink Relatively easy to High force required 1970 Zoltan constriction reservoir, forcing ink from a fabricate single nozzles Inefficient USP 3,683,212 constricted nozzle. from glass tubing as Difficult to integrate macroscopic structures with VLSI processes Coil/uncoil A coiled actuator uncoils or Easy to fabricate as a Difficult to fabricate USSN 09/112,815; coils more tightly. The motion planar VLSI process for non-planar devices 09/112,808; 09/112,811; of the free end of the actuator Small area required, Poor out-of-plane 09/112,812 ejects the ink. therefore low cost stiffness Bow The actuator bows (or Can increase the speed of Maximum travel is USSN 09/112,819; buckles) in the middle when travel constrained 09/113,096; 09/112,793 energized. Mechanically rigid High force required Push-Pull Two actuators control a The structure is pinned at Not readily suitable for USSN 09/113,096 shutter. One actuator pulls the both ends, so has a high ink jets which directly shutter, and the other pushes out-of-plane rigidity push the ink it Curl inwards A set of actuators curl Good fluid flow to the Design complexity USSN 09/113,095; inwards to reduce the volume region behind the actuator 09/112,807 of ink that they enclose. increases efficiency Curl outwards A set of actuators curl Relatively simple Relatively large chip area USSN 09/112,806 outwards, pressurizing ink in construction a chamber surrounding the actuators, and expelling ink from a nozzle in the chamber. Iris Multiple vanes enclose a High efficiency High fabrication complexity USSN 09/112,809 volume of ink. These Small chip area Not suitable for pigmented simultaneously rotate, inks reducing the volume between the vanes. Acoustic The actuator vibrates at a The actuator can be Large area required for 1993 Hadimioglu et al, vibration high frequency. physically distant from the efficient operation at EUP 550,192 ink useful frequencies 1993 Elrod et al, Acoustic coupling and EUP 572,220 crosstalk Complex drive circuitry Poor control of drop volume and position None In various ink jet designs No moving parts Various other tradeoffs are Silverbrook, EP the actuator does not move. required to eliminate 0771 658 A2 and related moving parts patent applications Tone-Jet NOZZLE REFILL METHOD Surface tension This is the normal way that Fabrication simplicity Low speed Thermal ink jet ink jets are refilled. After Operational simplicity Surface tension force Piezoelectric ink jet the actuator is energized, relatively small USSN 09/112,751; it typically returns rapidly compared to actuator 09/113,084; 09/112,779; to its normal position. This force 09/112,816; 09/112,819; rapid return sucks in air Long refill time usually 09/113,095; 09/112,809; through the nozzle opening. dominates the total 09/112,780; 09/113,083; The ink surface tension at the repetition rate 09/113,121; 09/113,122; nozzle then exerts a small 09/112,793; 09/112,794; force restoring the meniscus 09/113,128; 09/113,127; to a minimum area. This force 09/112,756; 09/112,755; refills the nozzle. 09/112,754; 09/112,811; 09/112,812; 09/112,813; 09/112,814; 09/112,764; 09/112,765; 09/112,767; 09/112,768; 09/112,807; 09/112,806; 09/112,820; 09/112,821 Shuttered Ink to the nozzle chamber High speed Requires common ink USSN 09/113,066; oscillating ink is provided at at pressure Low actuator energy, as pressure oscillator 09/112,818; 09/112,772; pressure that oscillates at twice the the actuator need only May not be suitable for 09/112,815; 09/113,096; drop ejection frequency. open or close the shutter, pigmented inks 09/113,068; 09/112,808 When a drop is to be ejected, instead of ejecting the the shutter is opened for 3 ink drop half cycles: drop ejection, actuator return, and refill. The shutter is then closed to prevent the nozzle chamber emptying during the next negative pressure cycle. Refill actuator After the main actuator has High speed, as the nozzle Requires two independent USSN 09/112,778 ejected a drop a second is actively refilled actuators per nozzle (refill) actuator is energized. The refill actuator pushes ink into the nozzle chamber. The refill actuator returns slowly, to prevent its return from emptying the chamber again. Positive ink The ink is held a slight High refill rate, therefore Surface spill must be Silverbrook, EP pressure positive pressure. After the a high drop repetition rate prevented 0771 658 A2 and related ink drop is ejected, the nozzle is possible Highly hydrophobic print patent applications chamber fills quickly as head surfaces are required Alternative for: USSN surface tension and ink 09/112,751; 09/112,787; pressure both operate to refill 09/112,802; 09/112,803; the nozzle. 09/113,097; 09/113,099; 09/113,084; 09/112,779; 09/113,077; 09/113,061; 09/112,818; 09/112,816; 09/112,819; 09/113,095; 09/112,809; 09/112,780; 09/113,083; 09/113,121; 09/113,122; 09/112,793; 09/112,794; 09/113,128; 09/113,127; 09/112,756; 09/112,755; 09/112,754; 09/112,811; 09/112,812; 09/112,813; 09/112,814; 09/112,764; 09/112,765; 09/112,767; 09/112,768; 09/112,807; 09/112,806; 09/112,820; 09/112,821 METHOD OF RESTRICTING BACK-FLOW THROUGH INLET Long inlet The ink inlet channel to the Design simplicity Restricts refill rate Thermal ink jet channel nozzle chamber is made long Operational simplicity May result in a relatively Piezoelectric ink jet and relatively narrow, relying Reduces crosstalk large chip area USSN 09/112,807; on viscous drag to reduce Only partially effective 09/112,806 inlet back-flow. Positive ink The ink is under a positive Drop selection and Requires a method (such Silverbrook, EP pressure pressure, so that in the separation forces can be as a nozzle rim or effective 0771 658 A2 and related quiescent state some of the reduced hydrophobizing, or both) to patent applications ink drop already protrudes Fast refill time prevent flooding of the Possible operation of the from the nozzle. ejection surface of the following: This reduces the pressure in print head. USSN 09/112,751; the nozzle chamber which is 09/112,787; 09/112,802; required to eject a certain 09/112,803; 09/113,097; volume of ink. The reduction 09/113,099; 09/113,084; in chamber pressure results 09/112,778; 09/112,779; in a reduction in ink pushed 09/113,077; 09/113,061; out through the inlet. 09/112,816; 09/112,819; 09/113,095; 09/112,809; 09/112,780; 09/113,083; 09/113,121; 09/113,122; 09/112,793; 09/112,794; 09/113,128; 09/113,127; 09/112,756; 09/112,755; 09/112,754; 09/112,811; 09/112,813; 09/112,814; 09/112,764; 09/112,765; 09/112,767; 09/112,768; Baffle One or more baffles are The refill rate is not as Design complexity HP Thermal Ink Jet placed in the inlet ink flow. restricted as the long May increase fabrication Tektronix piezoelectric When the actuator is inlet method. complexity (e.g. ink jet energized, the rapid ink Reduces crosstalk Tektronix hot melt movement creates eddies Piezoelectric print heads). which restrict the flow through the inlet. The slower refill process is unrestricted, and does not result in eddies. Flexible flap In this method recently Significantly reduces back- Not applicable to most Canon restricts inlet disclosed by Canon, the flow for edge-shooter ink jet configurations expanding actuator (bubble) thermal ink jet devices Increased fabrication pushes on a flexible flap complexity that restricts the inlet. Inelastic deformation of polymer flap results in creep over extended use Inlet filter A filter is located between Additional advantage of Restricts refill rate USSN 09/112,803; the ink inlet and the nozzle ink filtration May result in complex 09/113,061; 09/113,083; chamber. The filter has a Ink filter may be construction 09/112,793; 09/113,128; multitude of small holes or fabricated with no 09/113,127 slots, restricting ink flow. additional process steps The filter also removes particles which may block the nozzle. Small inlet The ink inlet channel to the Design simplicity Restricts refill rate USSN 09/112,787; compared to nozzle chamber has a May result in a relatively 09/112,814; 09/112,820 nozzle substantially smaller cross large chip area section than that of the nozzle, Only partially effective resulting in easier ink egress out of the nozzle than out of the inlet. Inlet shutter A secondary actuator controls Increases speed of the Requires separate refill USSN 09/112,778 the position of a shutter, ink-jet print head actuator and drive circuit closing off the ink inlet when operation the main actuator is energized. The inlet is The method avoids the Back-flow problem Requires careful design to USSN 09/112,751; located problem of inlet back-flow is eliminated minimize the negative 09/112,802; 09/113,097; behind the by arranging the ink-pushing pressure behind the paddle 09/113,099; 09/113,084; ink-pushing surface of the actuator 09/112,779; 09/113,077; surface between the inlet and the 09/112,816; 09/112,819; nozzle. 09/112,809; 09/112,780; 09/113,121; 09/112,794; 09/112,756; 09/112,755; 09/112,754; 09/112,811; 09/112,812; 09/112,813; 09/112,765; 09/112,767; 09/112,768 Part of the The actuator and a wall of the Significant reductions in Small increase in USSN 09/113,804; actuator moves ink chamber are arranged so back-flow can be achieved fabrication complexity 09/113,095; 09/113,122; to shut off that the motion of the actuator Compact designs possible 09/112,764 the inlet closes off the inlet. Nozzle actuator In some configurations of ink Ink back-flow problem is None related to ink back-flow Silverbrook, EP does not jet, there is no expansion or eliminated on actuation 0771 658 A2 and related result in ink movement of an actuator patent applications back-flow which may cause ink back- Valve-jet flow through the inlet. Tone-jet NOZZLE CLEARING METHOD Normal All of the nozzles are fired No added complexity May not be sufficient Most ink jet systems nozzle firing periodically, before the ink on the print head to displace dried ink USSN 09/112,751; has a chance to dry. When not 09/112,787; 09/112,802; in use the nozzles are sealed 09/112,803; 09/113,097; (capped) against air. 09/113,099; 09/113,084; The nozzle firing is usually 09/112,778; 09/112,779; performed during a special 09/113,077; 09/113,061; clearing cycle, after first 09/112,816; 09/112,819; moving the print head to a 09/113,095; 09/112,809; cleaning station. 09/112,780; 09/113,083; 09/113,121; 09/113,122; 09/112,793; 09/112,794; 09/113,128; 09/113,127; 09/112,756; 09/112,755; 09/112,754; 09/112,811; 09/112,813; 09/112,814; 09/112,764; 09/112,765; 09/112,767; 09/112,768; 09/112,807; 09/112,806; 09/112,820; 09/112,821 Extra In systems which heat the ink, Can be highly effective if Requires higher drive Silverbrook, EP power to but so not boil it under the heater is adjacent to voltage for clearing 0771 658 A2 and related ink heater normal situations, nozzle the nozzle May require larger drive patent applications clearing can be achieved by transistors over-powering the heater and boiling ink at the nozzle. Rapid The actuator is fired in rapid Does not require extra Effectiveness depends May be used with: USSN succession succession. In some drive circuits on the print substantially upon the 09/112,751; 09/112,787; of actuator configurations, this may cause head configuration of the ink 09/112,802; 09/112,803; pulses heat build-up at the nozzle Can be readily controlled jet nozzle 09/113,097; 09/113,099; which boils the ink, clearing and initiated by digital 09/113,084; 09/112,778; the nozzle. In other situations, logic 09/112,779; 09/113,077; it may cause sufficient 09/112,816; 09/112,819; vibrations to dislodge clogged 09/113,095; 09/112,809; nozzles. 09/112,780; 09/113,083; 09/113,121; 09/112,793; 09/112,794; 09/113,128; 09/113,127; 09/112,756; 09/112,755; 09/112,754; 09/112,811; 09/112,813; 09/112,814; 09/112,764; 09/112,765; 09/112,767; 09/112,768; 09/112,807; 09/112,806; 09/112,820; 09/112,821 Extra power Where an actuator is not A simple solution where Not suitable where there May be used with: USSN to ink pushing normally driven to the limit applicable is a hard limit to 09/112,802; 09/112,778; actuator of its motion, nozzle clearing actuator movement 09/112,819; 09/113,095; may be assisted by providing 09/112,780; 09/113,083; an enhanced drive signal to 09/113,121; 09/112,793; the actuator. 09/113,128; 09/113,127; 09/112,756; 09/112,755; 09/112,765; 09/112,767; 09/112,768; 09/112,807; 09/112,806; 09/112,820; 09/112,821 Acoustic An ultrasonic wave is applied A high nozzle clearing High implementation cost if USSN 09/113,066; resonance to the ink chamber. This wave capability can be achieved system does not already 09/112,818; 09/112,772; is of an appropriate amplitude May be implemented at include an acoustic actuator 09/112,815; 09/113,096; and frequency to cause very low cost in systems 09/113,068; 09/112,808 sufficient force at the nozzle which already include to clear blockages. This is acoustic actuators easiest to achieve if the ultrasonic wave is at a resonant frequency of the ink cavity. Nozzle A microfabricated plate is Can clear severely Accurate mechanical Silverbrook, EP clearing plate pushed against the nozzles. clogged nozzles alignment is required 0771 658 A2 and related The plate has a post for every Moving parts are required patent applications nozzle. A post moves through There is risk of damage to each nozzle, displacing dried the nozzles ink. Accurate fabrication is required Ink pressure The pressure of the ink is May be effective where Requires pressure pump or May be used with ink pulse temporarily increased so that other methods cannot other pressure actuator jets covered by USSN ink streams from all of the be used Expensive 09/112,751; 09/112,787; nozzles. This may be used in Wasteful of ink 09/112,802; 09/112,803; conjunction with actuator 09/113,097; 09/113,099; energizing. 09/113,084; 09/113,066; 09/113,778; 09/112,779; 09/113,077; 09/113,061; 09/112,818; 09/112,816; 09/112,772; 09/112,819; 09/112,815; 09/113,096; 09/113,068; 09/113,095; 09/112,808; 09/112,809; 09/112,780; 09/113,083; 09/113,121; 09/113,122; 09/112,793; 09/112,794; 09/113,128; 09/113,127; 09/112,756; 09/112,755; 09/112,754; 09/112,811; 09/112,812; 09/112,813; 09/112,814; 09/112,764; 09/112,765; 09/112,767; 09/112,768; 09/112,807; 09/112,806; 09/112,820; 09/112,821 Print head A flexible ‘blade’ Effective for planar Difficult to use if print Many ink jet systems wiper is wiped across the print print head surfaces head surface is non-planar head surface. The blade is Low cost or very fragile usually fabricated from a Requires mechanical parts flexible polymer, e.g. rubber Blade can wear out in high or synthetic elastomer. volume print systems Separate ink A separate heater is provided Can be effective where Fabrication complexity Can be used with many boiling heater at the nozzle although the other nozzle clearing ink jets covered normal drop e-ection methods cannot be used by USSN mechanism does not require Can be implemented at 09/112,751; 09/112,787; it. The heaters do not require no additional cost in 09/112,802; 09/112,803; individual drive circuits, as some ink jet 09/113,097; 09/113,099; many nozzles can be cleared configurations 09/113,084; 09/113,066; simultaneously, and no 09/113,778; 09/112,779; imaging is required. 09/113,077; 09/113,061; 09/112,818; 09/112,816; 09/112,772; 09/112,819; 09/112,815; 09/113,096; 09/113,068; 09/113,095; 09/112,808; 09/112,809; 09/112,780; 09/113,083; 09/113,121; 09/113,122; 09/112,793; 09/112,794; 09/113,128; 09/113,127; 09/112,756; 09/112,755; 09/112,754; 09/112,811; 09/112,812; 09/112,813; 09/112,814; 09/112,764; 09/112,765; 09/112,767; 09/112,768; 09/112,807; 09/112,806; 09/112,820; 09/112,821 NOZZLE PLATE CONSTRUCTION Electro- A nozzle plate is separately Fabrication simplicity High temperatures and Hewlett Packard formed fabricated from electroformed pressures are required to bond Thermal Ink jet nickel nickel, and bonded to the print nozzle plate head chip. Minimum thickness constraints Differential thermal expansion Laser Individual nozzle holes are No masks required Each hole must be Canon Bubblejet ablated or ablated by an intense UV Can be quite fast individually formed 1988 Sercel et al., drilled laser in a nozzle plate, Some control over nozzle Special equipment required SPIE, Vol. 998 Excimer polymer which is typically a profile is possible Slow where there are many Beam Applications, polymer such as polyimide Equipment required is thousands of nozzles per pp. 76-83 or polysulphone relatively low cost print head 1993 Watanabe et al., May produce thin burrs at USP 5,208,604 exit holes Silicon A separate nozzle plate is High accuracy is attainable Two part construction K. Bean, IEEE micro- micromachined from single High cost Transactions on machined crystal silicon, and bonded Requires precision alignment Electron Devices, to the print head wafer. Nozzles may be clogged Vol. ED-25, No. 10, by adhesive 1978, pp 1185-1195 Xerox 1990 Hawkins et al., USP 4,899,181 Glass Fine glass capillaries No expensive equipment Very small nozzle sizes 1970 Zoltan capillaries are drawn from glass tubing. required are difficult to form USP 3,683,121 This method has been used for Simple to make single Not suited for mass making individual nozzles, nozzles production but is difficult to use for bulk manufacturing of print heads with thousands of nozzles. Monolithic, The nozzle plate is deposited High accuracy (<1 μm) Requires sacrificial layer Silverbrook, EP surface as a layer using standard Monolithic under the nozzle plate to 0771 658 A2 and related micro- VLSI deposition techniques. Low cost form the nozzle chamber patent applications machined using Nozzles are etched in the Existing processes can Surface may be fragile to USSN 09/112,751; VLSI litho- nozzle plate using VLSI be used the touch 09/112,787; 09/112,803; graphic lithography and etching. 09/113,077; 09/113,061; processes 09/112,815; 09/113,096; 09/113,095; 09/112,809; 09/113,083; 09/112,793; 09/112,794; 09/113,128; 09/113,127; 09/112,756; 09/112,755; 09/112,754; 09/112,811; 09/112,813; 09/112,814; 09/112,764; 09/112,765; 09/112,767; 09/112,768; 09/112,807; 09/112,806; 09/112,820 Monolithic, The nozzle plate is a buried High accuracy (<1 μm) Requires long etch times USSN 09/112,802; etched etch stop in the wafer. Nozzle Monolithic Requires a support wafer 09/113,097; 09/113,099; through chambers are etched in the Low cost 09/113,084; 09/113,066; substrate front of the wafer, and the No differential expansion 09/113,778; 09/112,779; wafer is thinned from the 09/112,818; 09/112,816; back side. Nozzles are then 09/112,772; 09/112,819; etched in the etch stop layer. 09/113,068; 09/112,808; 09/112,780; 09/113,121; 09/113,122 No nozzle Various methods have been No nozzles to become Difficult to control Ricoh 1995 Sekiya et al plate tried to eliminate the clogged drop position accurately USP 5,412,413 nozzles entirely, to prevent Crosstalk problems 1993 Hadimioglu et al nozzle clogging. These EUP 550,192 include thermal bubble 1993 Elrod et al mechanisms and acoustic EUP 572,220 lens mechanisms Trough Each drop ejector has a Reduced manufacturing Drop firing direction USSN 09/112,812 trough through which a paddle complexity is sensitive to wicking. moves. There is no nozzle Monolithic plate. Nozzle slit The elimination of nozzle No nozzles to become Difficult to control drop 1989 Saito et al instead of holes and replacement by a clogged position accurately USP 4,799,068 individual slit encompassing many Crosstalk problems nozzles actuator positions reduces nozzle clogging, but increases crosstalk due to ink surface waves DROP EJECTION DIRECTION Edge Ink flow is along the Simple construction Nozzles limited to edge Canon Bubblejet 1979 (‘edge surface of the chip, and ink No silicon etching required High resolution is difficult Endo et al GB patent shooter’) drops are ejected from the Good heat sinking via Fast color printing 2,007,162 chip edge. substrate requires one print head Xerox heater-in-pit Mechanically strong per color 1990 Hawkins et al Ease of chip handing USP 4,899,181 Tone-jet Surface Ink flow is along the surface No bulk silicon etching Maximum ink flow is Hewlett-Packard TIJ (‘roof of the chip, and ink drops are required severely restricted 1982 Vaught et al shooter’) ejected from the chip surface, Silicon can make an USP 4,490,728 normal to the plane of the effective heat sink USSN 09/112,787 chip. Mechanical strength 09/113,077; 09/113,061; 09/113,095; 09/112,809 Through chip, Ink flow is through the chip, High ink flow Requires bulk Silverbrook, EP forward (‘up and ink drops are ejected from Suitable for pagewidth silicon etching 0771 658 A2 and related shooter’) surface of the chip. print heads patent applications High nozzle packing USSN 09/112,803; density 09/112,815; 09/113,096; therefore low 09/113,083; 09/112,793; manufacturing cost 09/112,794; 09/113,128; 09/113,127; 09/112,756; 09/112,755; 09/112,754; 09/112,811; 09/112,812; 09/112,813; 09/112,814; 09/112,764; 09/112,765; 09/112,767; 09/112,768; 09/112,807; 09/112,806; 09/112,820; 09/112,821 Through chip, Ink flow is through the chip, High ink flow Requires wafer thinning USSN 09/112,751; reverse and ink drops are ejected from Suitable for pagewidth Requires special handling 09/112,802; 09/113,097; (‘down the rear surface of the chip. print heads during manufacture 09/113,099; 09/113,084; shooter’) High nozzle packing 09/113,066; 09/113,778; density 09/112,779; 09/112,818; therefore low 09/112,816; 09/112,772; manufacturing cost 09/112,819; 09/113,068; 09/112,808; 09/112,780; 09/113,121; 09/113,122 Through Ink flow is through the Suitable for Pagewidth print heads Epson Stylus actuator actuator, which is not piezoelectric print heads require several thousand Tektronix hot melt fabricated as part of the same connections to drive circuits piezoelectric ink jets substrate as the drive Cannot be manufactured transistors. in standard CMOS fabs Complex assembly required INK TYPE Aqueous, Water based ink which Environmentally friendly Slow drying Most existing ink jets dye typically contains: water, dye No odor Corrosive USSN 09/112,751; surfactant, humectant, and Bleeds on paper 09/112,787; 09/112,802; biocide. May strikethrough 09/112,803; 09/113,097; Modern ink dyes have high Cockles paper 09/113,099; 09/113,084; water-fastness, light 09/113,066; 09/113,778; fastness 09/113,779; 09/113,077; 09/113,061; 09/112,818; 09/112,816; 09/113,772; 09/112,819; 09/112,815; 09/113,096; 09/113,068; 09/113,095; 09/112,808; 09/112,809; 09/113,780; 09/113,083; 09/113,121; 09/113,122; 09/112,793; 09/112,794; 09/113,128; 09/113,127; 09/112,756; 09/112,755; 09/112,754; 09/112,811; 09/112,812; 09/112,813; 09/112,814; 09/112,764; 09/112,765; 09/112,767; 09/112,768; 09/112,807; 09/112,806; 09/112,820; 09/112,821 Silverbrook, EP 0771 658 A2 and related patent applications Aqueous, Water based ink which Environmentally friendly Slow drying USSN 09/112,787; pigment typically contains: water, No odor Corrosive 09/112,803; 09/112,808; pigment, surfactant, Reduced bleed Pigment may clog nozzles 09/113,122; 09/112,793; humectant, and biocide. Reduced wicking Pigment may clog 09/113,127 Pigments have an advantage Reduced strikethrough actuator mechanisms Silverbrook, EP in reduced bleed, wicking and Cockles paper 0771 658 A2 and related strikethrough. patent applications Piezoelectric ink-jets Thermal ink jets (with significant restrictions) Methyl MEK is a highly volatile Very fast drying Odorous USSN 09/112,751; Ethyl solvent used for industrial Prints on various Flammable 09/112,787; 09/112,802; Ketone printing on difficult substrates such as metals 09/112,803; 09/113,097; (MEK) surfaces such as aluminum and plastics 09/113,099; 09/113,084; cans. 09/113,066; 09/113,778; 09/113,779; 09/113,077; 09/113,061; 09/112,818; 09/112,816; 09/113,772; 09/112,819; 09/112,815; 09/113,096; 09/113,068; 09/113,095; 09/112,808; 09/112,809; 09/113,780; 09/113,083; 09/113,121; 09/113,122; 09/112,793; 09/112,794; 09/113,128; 09/113,127; 09/112,756; 09/112,755; 09/112,754; 09/112,811; 09/112,812; 09/112,813; 09/112,814; 09/112,764; 09/112,765; 09/112,767; 09/112,768; 09/112,807; 09/112,806; 09/112,820; 09/112,821 Alcohol Alcohol based inks can be Fast drying Slight odor USSN 09/112,751; (ethanol, used where the printer must Operates at sub-freezing Flammable 09/112,787; 09/112,802; 2-butanol, operate at temperatures below temperatures 09/112,803; 09/113,097; and others) the freezing point of water. Reduced paper cockle 09/113,099; 09/113,084; An example of this is Low cost 09/113,066; 09/113,778; in-camera consumer 09/113,779; 09/113,077; photographic printing. 09/113,061; 09/112,818; 09/112,816; 09/113,772; 09/112,819; 09/112,815; 09/113,096; 09/113,068; 09/113,095; 09/112,808; 09/112,809; 09/113,780; 09/113,083; 09/113,121; 09/113,122; 09/112,793; 09/112,794; 09/113,128; 09/113,127; 09/112,756; 09/112,755; 09/112,754; 09/112,811; 09/112,812; 09/112,813; 09/112,814; 09/112,764; 09/112,765; 09/112,767; 09/112,768; 09/112,807; 09/112,806; 09/112,820; 09/112,821 Phase change The ink is solid at room No drying time - ink High viscosity Tektronix hot melt (hot melt) temperature, and is melted instantly freezes on the Printed ink typically has piezoelectric ink jets in the print head before print medium a ‘waxy’ feel 1989 Nowak jetting. Hot melt inks are Almost any print medium Printed pages may ‘block’ USP 4,820,346 usually wax based, with a can be used Ink temperature may be USSN 09/112,751; melting point around No paper cockles occurs above the curie point of 09/112,787; 09/112,802; 80° C. After jetting No wicking occurs permanent magnets 09/112,803; 09/113,097; the ink freezes almost No bleed occurs Ink heaters consume power 09/113,099; 09/113,084; instantly upon contacting No strikethrough occurs Long warm-up time 09/113,066; 09/113,778; the print medium or a 09/113,779; 09/113,077; transfer roller. 09/113,061; 09/112,818; 09/112,816; 09/113,772; 09/112,819; 09/112,815; 09/113,096; 09/113,068; 09/113,095; 09/112,808; 09/112,809; 09/113,780; 09/113,083; 09/113,121; 09/113,122; 09/112,793; 09/112,794; 09/113,128; 09/113,127; 09/112,756; 09/112,755; 09/112,754; 09/112,811; 09/112,812; 09/112,813; 09/112,814; 09/112,764; 09/112,765; 09/112,767; 09/112,768; 09/112,807; 09/112,806; 09/112,820; 09/112,821 Oil Oil based inks are High solubility medium for High viscosity: this is a USSN 09/112,751; extensively used in offset some dyes significant limitation for 09/112,787; 09/112,802; printing. They have Does not cockle paper use in ink jets, which 09/112,803; 09/113,097; advantages in improved Does not wick through usually require a low 09/113,099; 09/113,084; characteristics on paper paper viscosity. Some short 09/113,066; 09/113,778; (especially no wicking chain and multi-branced 09/113,779; 09/113,077; or cockle). Oil soluble oils have a sufficiently 09/113,061; 09/112,818; dies and pigments are low viscosity. 09/112,816; 09/113,772; required Slow drying 09/112,819; 09/112,815; 09/113,096; 09/113,068; 09/113,095; 09/112,808; 09/112,809; 09/113,780; 09/113,083; 09/113,121; 09/113,122; 09/112,793; 09/112,794; 09/113,128; 09/113,127; 09/112,756; 09/112,755; 09/112,754; 09/112,811; 09/112,812; 09/112,813; 09/112,814; 09/112,764; 09/112,765; 09/112,767; 09/112,768; 09/112,807; 09/112,806; 09/112,820; 09/112,821 Micro- A microemulsion is a stable, Stops ink bleed Viscosity higher than water USSN 09/112,751; emulsion self forming emulsion of oil, High dye solubility Cost is slightly higher than 09/112,787; 09/112,802; water, and surfactant. The Water, oil, and water based ink 09/112,803; 09/113,097; characteristic drop size is amphiphilic soluble dies High surfactant concentration 09/113,099; 09/113,084; less than 100 nm, and is can be used required (around 5%) 09/113,066; 09/113,778; determined by the preferred Can stabilize pigment 09/113,779; 09/113,077; curvature of the surfactant. suspensions 09/113,061; 09/112,818; 09/112,816; 09/113,772; 09/112,819; 09/112,815; 09/113,096; 09/113,068; 09/113,095; 09/112,808; 09/112,809; 09/113,780; 09/113,083; 09/113,121; 09/113,122; 09/112,793; 09/112,794; 09/113,128; 09/113,127; 09/112,756; 09/112,755; 09/112,754; 09/112,811; 09/112,812; 09/112,813; 09/112,814; 09/112,764; 09/112,765; 09/112,767; 09/112,768; 09/112,807; 09/112,806; 09/112,820; 09/112,821 

I claim:
 1. A camera device comprising: an area image sensor adapted to sense an image; an image store adapted to store the sensed image; an orientation sensor adapted to sense the camera's rotational orientation with respect to gravity; a processor adapted to process said sensed image utilizing said sensed camera orientation by applying an orientation-dependent transform to said sensed image to produce a transformed image; and an inbuilt printer for printing out said transformed image on print media, wherein said orientation-dependent transform is selected from the group comprising: (i) detecting, using said sensed camera orientation, at least one face within said sensed image, and altering said sensed image in relation to said at least one detected face to produce said transformed image; and (ii) placing, at an orientation consistent with said sensed camera orientation, textual information within said sensed image to produce said transformed image.
 2. The camera device as claimed in claim 1 wherein said orientation-dependent transform includes the distorting of features within said sensed image to produce said transformed image.
 3. A method of processing an image captured by a digital camera device comprising: an area image sensor adapted to sense an image; an image store adapted to store the sensed image; an orientation sensor adapted to sense the camera's rotational orientation with respect to gravity; a processor adapted to process said sensed image to produce a transformed image; and an inbuilt printer adapted to print out said transformed image, said method comprising the steps of: (a) sensing, via said orientation sensor, the camera's rotational orientation with respect to gravity; (b) processing, via said processor, said sensed image utilizing said sensed camera orientation by applying an orientation-dependent transform to said sensed image to produce said transformed image; (c) printing, via said inbuilt printer, said transformed image, wherein said orientation-dependent transform is selected from the group comprising: (i) detecting, using said sensed camera orientation, at least one face within said sensed image, and altering said sensed image in relation to said at least one detected face to produce said transformed image; and (ii) placing, at an orientation consistent with said sensed camera orientation, textual information within said sensed image to produce said transformed image.
 4. A method as claimed in claim 3 wherein said orientation-dependent transform further comprises one or more of: (iii) the distortion of features within said sensed image to produce said transformed image; and (iv) the placement of information relevant to facial features of animals or humans appearing within the image, to produce said transformed image. 